Abstract: This internal combustion engine includes a piston, an oil jet that operates at a predetermined operating pressure to supply oil to the piston, and a hydraulic controller provided upstream of an oil passage including the oil jet. The hydraulic controller includes a constantly opened first passage through which the oil having a pressure lower than the predetermined operating pressure is supplied to the oil jet, a second passage provided alongside of the first passage and being openable and closable, through which the oil having a pressure higher than the predetermined operating pressure is supplied to the oil jet in combination with the first passage in a state where the same is opened, and an opening-closing control portion that controls the second passage to be in an open state when actuating the oil jet, and controls the second passage to be in a closed state when stopping actuating the oil jet.

Abstract: This internal combustion engine includes a piston, an oil jet that operates at a predetermined operating pressure to supply oil to the piston, and a hydraulic controller provided upstream of an oil passage including the oil jet. The hydraulic controller includes a constantly opened first passage through which the oil having a pressure lower than the predetermined operating pressure is supplied to the oil jet, a second passage provided alongside of the first passage and being openable and closable, through which the oil having a pressure higher than the predetermined operating pressure is supplied to the oil jet in combination with the first passage in a state where the same is opened, and an opening-closing control portion that controls the second passage to be in an open state when actuating the oil jet, and controls the second passage to be in a closed state when stopping actuating the oil jet.

Abstract: An oil pump includes: an inner rotor rotatable with a drive shaft in a unified manner on a drive-rotation axis; an outer rotor which has inner teeth configured to engage with outer teeth of the inner rotor and is rotatable about a driven axis eccentric to the drive-rotation axis; and an adjustment ring for rotatably supporting the outer rotor. A guide means which allows the adjustment ring to rotate about the driven axis, while allowing the driven axis to revolve about the drive-rotation axis, is formed of: first and second arm portions provided on the adjustment ring; and first and second guide faces with which the first and second arm portions are brought into slidable contact.

Abstract: An oil pump includes a capacity adjustment mechanism that changes the pump capacity by moving a tubular body in a tube radial direction, with a pump chamber formed between the tubular body and an outer circumference side of a rotor, a first spring biasing the tubular body in a direction in which pump capacity increases, a control valve that converts oil pressure of the oil pump into control pressure and causes the control pressure to act on the capacity adjustment mechanism, and a second spring biasing a valve body in order to set the control pressure in the control valve. The relationship of the biasing forces of the first and second springs is set so that pump capacity is set to maximum when the engine rotational speed is less than a predetermined value, and so that pump capacity is reduced when the engine rotational speed exceeds a predetermined value.

Abstract: An oil pump includes a capacity adjustment mechanism that changes the pump capacity by moving a tubular body in a tube radial direction, with a pump chamber formed between the tubular body and an outer circumference side of a rotor, a first spring biasing the tubular body in a direction in which pump capacity increases, a control valve that converts oil pressure of the oil pump into control pressure and causes the control pressure to act on the capacity adjustment mechanism, and a second spring biasing a valve body in order to set the control pressure in the control valve. The relationship of the biasing forces of the first and second springs is set so that pump capacity is set to maximum when the engine rotational speed is less than a predetermined value, and so that pump capacity is reduced when the engine rotational speed exceeds a predetermined value.

Abstract: An oil pump includes: an inner rotor rotatable with a drive shaft in a unified manner on a drive-rotation axis; an outer rotor which has inner teeth configured to engage with outer teeth of the inner rotor and is rotatable about a driven axis eccentric to the drive-rotation axis; and an adjustment ring for rotatably supporting the outer rotor. A guide means which allows the adjustment ring to rotate about the driven axis, while allowing the driven axis to revolve about the drive-rotation axis, is formed of: first and second arm portions provided on the adjustment ring; and first and second guide faces with which the first and second arm portions are brought into slidable contact.

Abstract: An electromagnetic valve unit comprises a first electromagnetic valve provided at a cover, which is positioned at one end portion of an engine, for controlling an amount of hydraulic oil supplied from a hydraulic pressure source to a first hydraulic mechanism, a second electromagnetic valve provided at the cover so as to be next to the first electromagnetic valve for controlling an amount of hydraulic oil supplied from the hydraulic pressure source to a second hydraulic mechanism and an oil filter provided between the first electromagnetic valve and the second electromagnetic valve and connected to each of the first and the second electromagnetic valves in order to filter the hydraulic oil supplied to each of the first and the second electromagnetic valves.

Abstract: A relief valve for regulating discharged oil pressure of an oil pump at a predetermined level comprises a cylinder including a bore therein and relief grooves formed symmetrically relatively to an axial center of the bore, while each of the relief grooves has a respective opening to an inner peripheral portion of the bore; a valve body disposed in the cylinder so as to be slidably moved in the bore in response to the discharged oil pressure supplied into the bore at one side of the valve body; a spring provided in the other side of the valve body constantly urging the valve body toward the one side of the valve body so as to close the openings of the relief grooves by the valve body; and an adjusting means for adjusting a change rate of an opening area of the relief grooves relatively to one slide movement of the valve body against the force of the spring so that the change rate of the opening area at the beginning of slide movement of the valve body is smaller than that at the end of the slide movement of th

Abstract: A relief valve for regulating discharged oil pressure of an oil pump at a predetermined level comprises a cylinder including a bore therein and relief grooves formed symmetrically relatively to an axial center of the bore, while each of the relief grooves has a respective opening to an inner peripheral portion of the bore; a valve body disposed in the cylinder so as to be slidably moved in the bore in response to the discharged oil pressure supplied into the bore at one side of the valve body; a spring provided in the other side of the valve body constantly urging the valve body toward the one side of the valve body so as to close the openings of the relief grooves by the valve body; and an adjusting means for adjusting a change rate of an opening area of the relief grooves relatively to one slide movement of the valve body against the force of the spring so that the change rate of the opening area at the beginning of slide movement of the valve body is smaller than that at the end of the slide movement of th

Abstract: An automatic hydraulic tensioner according to the present invention is provided with a communication mechanism for allowing a space radially inside a plunger-side end wire portion of a coil spring to communicate with a small clearance between the plunger and a cylinder. This automatic hydraulic tensioner thus succeeds, with a simple structure, in preventing bubbles from remaining within a pressure chamber and appropriately maintaining the tension applied to a power transmitting means such as a belt, a chain or the like.